There have been many attempts to provide a useful process for engraving and/or embossing of glass and ceramic articles.
U.S. Pat. No. 2,065,406, issued in 1936 to Silverman, entitled "ORNAMENTED GLASS AND METHOD OF PRODUCING SAME", discloses a method of producing a bas-relief visual effect by engraving the painted reverse surface of a glass plate, and forcing metal foil into the engraved area.
U.S. Pat. No. 2,555,007, issued in 1951 to Fuller, Jr., entitled "METHOD OF FORMING DESIGNS IN RELIEF", discloses a method of forming designs in relief to produce a multi-color design by selective sandblasting of a plate laminated from layers of glass.
U.S. Pat. No. 3,267,621, issued in 1966 to Meyers et al, entitled, "ARTICLE DECORATING", discloses a method of decorating glassware by using a machine, designed for applying silkscreened painted decorations, to apply an etching mask.
U.S. Pat. No. 3,328,925, issued in 1967 to Hewitt, entitled "PROCESS FOR ORNAMENTING GLASS ARTICLES", discloses a method of producing three-dimensional designs on glass using a sandblasting machine with a conveyor system, and a precut shield, prefabricated shields, or injection-molded mask.
The prior art does not solve the problems of engraving and/or embossing curved or irregular glassware or ceramics. Furthermore, the prior art techniques mentioned above, are too complex and expensive.
Other known prior art involves the use of precut masks of various materials to be applied to the surface of glassware. These precut masks are unsatisfactory on contoured surfaces and do not conform to the surface to protect those areas not to be engraved. This results in irregular and blurred engraving, and will not allow engraving of fine details. The instant invention discloses a method of making and using precut masks which overcomes these difficulties.
Another known method involves the use of a precut rubber mask, used for engraving letters and symbols in varying combinations. These rubber masks may initially conform to a contoured surface, but lose their resiliency, and flutter against the surface, resulting in blurred detail. This type of mask is also unsuitable for engraving narrow lines and fine detail.